CTD every time I engage a battle

If I autoresolve, the game will run smooth, if I choose to fight the game will ctd. I can reload the game and fight the battle (I always save prior to a battle), but the game won't run the script till after the battle is over. The save point begins at the challenge screen, and after I fight the battle then I can turn on the script.

I'm playing the romans, ctds happen during my iberian invasion.

Don't save while on the challange screen. It may cause CTD's.

Install the fixes if you haven't already.

Quit the game every 2 or 3 hours to kill the memory leak RTW suffers (and which causes CTD's).